A physical impact to the head of a person may cause serious injury or death. To reduce the probability of such consequences, protective gear, such as a helmet, is often used in activities that are associated with an increased level of risk for a head injury. Examples of such activities include, but are not limited to skiing, snowboarding, sledding, ice skating, bicycling, rollerblading, rock climbing, skate boarding, and motorcycling. In general, a helmet is designed to maintain its structural integrity and stay secured to the head of a wearer during an impact.
Accordingly, a skiing or snowboarding helmet, referred to generally herein as an “alpine helmet” is designed to protect the wearer's head, including to absorb and dissipate energy during an impact with a surface, such as the ground. In this regard, alpine helmet interiors include impact attenuating materials such as an arrangement of padding and/or foam, wherein the impact attenuating materials cover and contact a significant extent of the wearer's head.
Designing an alpine helmet presents unique challenges because of the relatively wide range of temperatures to which the impact attenuating materials are exposed and within which the impact attenuating materials must remain effective. Skiing and snowboarding activities generally take place in relatively cold ambient temperatures. Indeed, it is not uncommon for skiers and snowboarders to experience temperatures or wind chills exceeding −25° C. Thus, an alpine helmet should effectively protect the wearer when the helmet is quite cold, for example after a break in activity when the helmet is taken off and left outside. Of course, the helmet should also effectively protect the wearer when the helmet is relatively warm, either because of warmer ambient conditions or because heat transfer from the wearer's head has warmed the helmet materials after the helmet has been worn for a period of time.
Most impact attenuating materials used for alpine and other types of helmets generally get harder as the temperature of the material is reduced. Such materials also generally get softer as the temperature of the material increases. These common material properties present a challenge for the designer seeking to develop an alpine helmet that provides consistent protection and energy attenuation over a wide range of temperatures. What is needed is a protective alpine helmet that maintains its protective properties throughout a wide range of ambient temperatures.
The present invention is provided to solve these limitations and to provide advantages and aspects not provided by conventional alpine helmets. A full discussion of the features and advantages of the present invention is deferred to the following detailed description, which proceeds with reference to the accompanying drawings.